1. Field of the Invention
The present invention relates to a contact structure of a socket connector to be provided in a PC (Personal Computer) card or the like, and more particularly, to a contact structure of a socket connector which is suited to the shortening the arrangement pitch of socket contacts.
2. Description of the Related Art
Built into a PC card to be loaded into a notebook personal computer or the like are a socket connector including many socket contacts fixed on an insulating housing, a circuit substrate to be connected to the socket contacts, and the like. In attaching the PC card to a pin connector on the side of an external apparatus, contact pins of the pin connector are respectively inserted into the socket contacts from the leading end of the socket connector. In recent years, there has been a strong demand that the arrangement pitch of the socket contacts be shortened to, for example, 1.27 mm in such a socket connector of the PC card. Japanese Unexamined Patent Publication No. 8-45592 has proposed a socket connector which is adapted for such pitch reduction.
FIG. 24 is a side view of a socket contact in the socket connector disclosed in the aforesaid publication. As shown in FIG. 24, one socket contact 1 is provided with a pair of contact leaves 2 and 3 for gripping a contact pin to be inserted, a connecting section 4 for connecting the contact leaves 2 and 3, a holding section 5 to be press-fitted and fixed in a housing, and a terminal section 6 extending backward from the holding section 5. The contact leaves 2 and 3 are perpendicularly bent at the diagonal positions on the long narrow connecting section 4, and the holding section 5 extends backward from one contact leaf 2.
FIG. 25 is a development view showing a state in which an electrically conductive flat metal plate as a raw material of the socket contact 1 is stamped. As shown in FIG. 25, one contact leaf 3 of one socket contact crosses the other contact leaf 2 of the adjoining socket contact, and comes between the contact leaf 2 and the connecting section 4 of the adjoining socket contact. The electrically conductive flat metal plate thus stamped is perpendicularly bent at the positions shown by the two-dot chained lines in FIG. 25, thereby obtaining many socket contacts 1 arranged with a predetermined pitch P.
In a development state of the aforesaid conventional socket contacts before they are bent into the final shape, one of the contact leaves formed in one socket contact comes inside the contact leaf of the adjoining socket contact. Therefore, the arrangement pitch P of the socket contacts in stamping can be reduced to the small pitch required for the socket connector, and a socket connector having socket contacts arranged with a small pitch, for example, 1.27 mm, can be realized. However, on the other hand, the structure of a die for use in stamping the socket contacts is extremely complicated, which increases the die cost and impedes the speeding-up of the processing cycle.